Research Xi'an Metropolitan Spatial Pattern Of Urban Agriculture Functions

With the development of industrialization and rapid expansion of urbanization in the region, metropolitan area and megalopolis have appeared, economic growth is accelerating. But it also brings a series of problems, such as the density of urban population is increasing, shortage of resources, the ecological environment is deteriorating, the gap between urban and rural areas is increasing. Urban agriculture is a new type of agriculture along with urban development, there is very close interdependence between socio-economic of metropolitan and urban agriculture, and urban agriculture has various functions such as economic, social and ecological function. Therefore, it is an effective way and realistic choice to solve above-mentioned problems. Xi’an metropolitan area is core of Guanzhong-Tianshui Economic Zone in the northwest of China. In recent years, the urban development of xi’an is fast, however, air pollution is worsening. The multifunction of urban agriculture is obvious increasingly, it can prevent urban excessively spread, regulate urban microclimate, increase the income of rural residents, reduce the gap between urban and rural areas, provide the fresh, safe agricultural products and beautiful environment to travel for city residents, and it can also meet the material and spititual needs of urban residents. Based on data of TM image and socio-economic statistics, employing evaluation method of ecosystem services, RS, GIS and SPSS softwares, the agricultural functions of Xi’an metropolitan area in1999,2004,2010were evaluated and its temporal and spatial evolution were also analyzed in this paper. The paper also study on regionalization of urban agricultural functions in1999,2010. It is helpfull to promote the rational allocation of various functional areas and urban agricultural resources, comprehensively optimize agricultural space layout, improve competitiveness of urban agriculture. It is of important theoretical significance to enhance social attention to develop urban agriculture in Xi’an metropolitan area, improve the ecological environment, coordinate urban and rural development, promote sustained and rapid development of metropolitan area.Through research and analysis, these conclusions were reached:Firstly, the total value of urban agriculture was decreased at first then increasing in Xi’an metropolitan area. From1999to2004, the total value of urban agriculture reduced 3.1%; from2004to2010, the total value of urban agriculture increased10.3%. From1999to2004, the rapid growth of urban population and increase of the demand for housing result in the areas of farmland, woodland and grassland have been reduced; from2004to2010, further expansion of city, but because of the attention of nation to new rural construction and metropolitan positively response to the national policy of returning farmland, so the area of orchard greatly increase, the functional value is enhanced. The value of single urban agriculture is different, the value of ecological function was decreased with a trend of fluctuations, the value of production and employment were a trend of sustained growth. Urban expansion, deforestation and other undesirable exploitation and utilization result in the ecological function reduced, but social and economic development can improve agricultural value of production and social.Secondly, the value of urban agriculture is gradually increasing from urban core to edge of built-up area, there is high value in the southern and northern edges of metropolitan area, median and low value in the middle of metropolitan area; The total value outside the urban core was decreased and reduction was larger, the rest of region were increased, in which of Li-Quan increased largely. Agricultural land of perphery of urban core is decreasing because of urbanization, the area of orchard gradually increased in Li-Quan, the value of production and employment of orchard are higher. The spatial pattern of single urban agriculture is different, the high area of production mainly distributed in the north of metropolitan area, low-value distributed in Qinling Mountains in the southern of the study area; The spatial pattern of the employment is quite different, the highest value in the north of Weihe River against lowest value in the south of Weihe River; Generally, the value of ecological regulation of the northern is lower, the southern is higher. The agricultural langscape of central and northern is arable land and orchard, the southern is Qinling Mountains, its agricultural langscape is woodland and grassland; The value of production decreased largely around Xi’an against to increased largely in the north of Lan-Tian; The value of ecological regulation decreased largely in Chang-An and Lan-Tian against to increased largely in Li-Quan; The value of employment was a trend of decrease and the scope gradually expand in the surrounding of Xi’an, but the north of Weihe River was increased.Thirdly, The functional areas of urban agriculture were divided into the function of agricultural production, the function of agricultural production and employment security, ecological regulation, Leisure and Entertainment in Xi’an metropolitan area. Compared to1999, under the jurisdiction of each area varied in2010, which area of leisure and entertainment vary obviously, and its area expanded. With the improvement of material living standards of residents and the deterioration of the urban environment, the demand of people for leisure and tourism of urban agriculture become strong Increasingly. The status of urban agricultural leisure tourism will continue to enhance. The dominant function of urban agriculture can be affected by regional resources, economics and the level of urbanization, and vary with the strategic objectives of regioual development.